xref: /linux/ipc/syscall.c (revision ab52c59103002b49f2455371e4b9c56ba3ef1781)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * sys_ipc() is the old de-multiplexer for the SysV IPC calls.
4  *
5  * This is really horribly ugly, and new architectures should just wire up
6  * the individual syscalls instead.
7  */
8 #include <linux/unistd.h>
9 #include <linux/syscalls.h>
10 #include <linux/security.h>
11 #include <linux/ipc_namespace.h>
12 #include "util.h"
13 
14 #ifdef __ARCH_WANT_SYS_IPC
15 #include <linux/errno.h>
16 #include <linux/ipc.h>
17 #include <linux/shm.h>
18 #include <linux/uaccess.h>
19 
20 int ksys_ipc(unsigned int call, int first, unsigned long second,
21 	unsigned long third, void __user * ptr, long fifth)
22 {
23 	int version, ret;
24 
25 	version = call >> 16; /* hack for backward compatibility */
26 	call &= 0xffff;
27 
28 	switch (call) {
29 	case SEMOP:
30 		return ksys_semtimedop(first, (struct sembuf __user *)ptr,
31 				       second, NULL);
32 	case SEMTIMEDOP:
33 		if (IS_ENABLED(CONFIG_64BIT))
34 			return ksys_semtimedop(first, ptr, second,
35 			        (const struct __kernel_timespec __user *)fifth);
36 		else if (IS_ENABLED(CONFIG_COMPAT_32BIT_TIME))
37 			return compat_ksys_semtimedop(first, ptr, second,
38 			        (const struct old_timespec32 __user *)fifth);
39 		else
40 			return -ENOSYS;
41 
42 	case SEMGET:
43 		return ksys_semget(first, second, third);
44 	case SEMCTL: {
45 		unsigned long arg;
46 		if (!ptr)
47 			return -EINVAL;
48 		if (get_user(arg, (unsigned long __user *) ptr))
49 			return -EFAULT;
50 		return ksys_old_semctl(first, second, third, arg);
51 	}
52 
53 	case MSGSND:
54 		return ksys_msgsnd(first, (struct msgbuf __user *) ptr,
55 				  second, third);
56 	case MSGRCV:
57 		switch (version) {
58 		case 0: {
59 			struct ipc_kludge tmp;
60 			if (!ptr)
61 				return -EINVAL;
62 
63 			if (copy_from_user(&tmp,
64 					   (struct ipc_kludge __user *) ptr,
65 					   sizeof(tmp)))
66 				return -EFAULT;
67 			return ksys_msgrcv(first, tmp.msgp, second,
68 					   tmp.msgtyp, third);
69 		}
70 		default:
71 			return ksys_msgrcv(first,
72 					   (struct msgbuf __user *) ptr,
73 					   second, fifth, third);
74 		}
75 	case MSGGET:
76 		return ksys_msgget((key_t) first, second);
77 	case MSGCTL:
78 		return ksys_old_msgctl(first, second,
79 				   (struct msqid_ds __user *)ptr);
80 
81 	case SHMAT:
82 		switch (version) {
83 		default: {
84 			unsigned long raddr;
85 			ret = do_shmat(first, (char __user *)ptr,
86 				       second, &raddr, SHMLBA);
87 			if (ret)
88 				return ret;
89 			return put_user(raddr, (unsigned long __user *) third);
90 		}
91 		case 1:
92 			/*
93 			 * This was the entry point for kernel-originating calls
94 			 * from iBCS2 in 2.2 days.
95 			 */
96 			return -EINVAL;
97 		}
98 	case SHMDT:
99 		return ksys_shmdt((char __user *)ptr);
100 	case SHMGET:
101 		return ksys_shmget(first, second, third);
102 	case SHMCTL:
103 		return ksys_old_shmctl(first, second,
104 				   (struct shmid_ds __user *) ptr);
105 	default:
106 		return -ENOSYS;
107 	}
108 }
109 
110 SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
111 		unsigned long, third, void __user *, ptr, long, fifth)
112 {
113 	return ksys_ipc(call, first, second, third, ptr, fifth);
114 }
115 #endif
116 
117 #ifdef CONFIG_COMPAT
118 #include <linux/compat.h>
119 
120 #ifndef COMPAT_SHMLBA
121 #define COMPAT_SHMLBA	SHMLBA
122 #endif
123 
124 struct compat_ipc_kludge {
125 	compat_uptr_t msgp;
126 	compat_long_t msgtyp;
127 };
128 
129 #ifdef CONFIG_ARCH_WANT_OLD_COMPAT_IPC
130 int compat_ksys_ipc(u32 call, int first, int second,
131 	u32 third, compat_uptr_t ptr, u32 fifth)
132 {
133 	int version;
134 	u32 pad;
135 
136 	version = call >> 16; /* hack for backward compatibility */
137 	call &= 0xffff;
138 
139 	switch (call) {
140 	case SEMOP:
141 		/* struct sembuf is the same on 32 and 64bit :)) */
142 		return ksys_semtimedop(first, compat_ptr(ptr), second, NULL);
143 	case SEMTIMEDOP:
144 		if (!IS_ENABLED(CONFIG_COMPAT_32BIT_TIME))
145 			return -ENOSYS;
146 		return compat_ksys_semtimedop(first, compat_ptr(ptr), second,
147 						compat_ptr(fifth));
148 	case SEMGET:
149 		return ksys_semget(first, second, third);
150 	case SEMCTL:
151 		if (!ptr)
152 			return -EINVAL;
153 		if (get_user(pad, (u32 __user *) compat_ptr(ptr)))
154 			return -EFAULT;
155 		return compat_ksys_old_semctl(first, second, third, pad);
156 
157 	case MSGSND:
158 		return compat_ksys_msgsnd(first, ptr, second, third);
159 
160 	case MSGRCV: {
161 		void __user *uptr = compat_ptr(ptr);
162 
163 		if (first < 0 || second < 0)
164 			return -EINVAL;
165 
166 		if (!version) {
167 			struct compat_ipc_kludge ipck;
168 			if (!uptr)
169 				return -EINVAL;
170 			if (copy_from_user(&ipck, uptr, sizeof(ipck)))
171 				return -EFAULT;
172 			return compat_ksys_msgrcv(first, ipck.msgp, second,
173 						 ipck.msgtyp, third);
174 		}
175 		return compat_ksys_msgrcv(first, ptr, second, fifth, third);
176 	}
177 	case MSGGET:
178 		return ksys_msgget(first, second);
179 	case MSGCTL:
180 		return compat_ksys_old_msgctl(first, second, compat_ptr(ptr));
181 
182 	case SHMAT: {
183 		int err;
184 		unsigned long raddr;
185 
186 		if (version == 1)
187 			return -EINVAL;
188 		err = do_shmat(first, compat_ptr(ptr), second, &raddr,
189 			       COMPAT_SHMLBA);
190 		if (err < 0)
191 			return err;
192 		return put_user(raddr, (compat_ulong_t __user *)compat_ptr(third));
193 	}
194 	case SHMDT:
195 		return ksys_shmdt(compat_ptr(ptr));
196 	case SHMGET:
197 		return ksys_shmget(first, (unsigned int)second, third);
198 	case SHMCTL:
199 		return compat_ksys_old_shmctl(first, second, compat_ptr(ptr));
200 	}
201 
202 	return -ENOSYS;
203 }
204 
205 COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
206 	u32, third, compat_uptr_t, ptr, u32, fifth)
207 {
208 	return compat_ksys_ipc(call, first, second, third, ptr, fifth);
209 }
210 #endif
211 #endif
212